feature request: compiler switch to output compiler defined version constants

[BCS]

Steven Schveighoffer wrote:
> It would be nice if dmd -showversions output all the version constants 
> defined by the compiler.  Why do I say this?  Because it's much more 
> convenient than searching through the digital mars web site for predefined 
> constants, then trying to figure out if those constants are defined or not 
> by trying to compile a file with those version constants in it.  And this 
> should be done in both D 1.0 and 2.0, as it doesn't affect the language.
> 
> BTW, if there is already some way to do this, please let me know :)
> 
> -Steve 
> 
> 

you still need to find the things to check but this will give you a yes no:

mixin(DefinedP!("ver123"));

template DefinedP(char[] ver)
{
   const char[] DefinedP = 
"version("~ver~"){pragma(msg,`+"~ver~"`)}else{pragma(msg,`-"~ver~"`)}";
}